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iamthecore (September 3, 2008 at 2:27 am)
DNA polymerase 1 just adds the right nucleotides to the stand. In order for this to happen, Polymerase 3 has to attach to RNA to get the strand started for replication once the helicase unwinds the strand. That's the only reason RNA attaches to DNA just so that DNA can attach. It's just how it works..
iamthecore (September 3, 2008 at 2:23 am)
DNA Pol 3 adds DNA nucleotides to the RNA nucleotides before DNA is replicated. The RNA primer is then removed by DNA Pol 1 so that DNA nucleotides are can be added on the strand. Once Pol 1 takes out the RNA primer, it replaces it with DNA. The fragmented DNA, which are called Okazaki fragments is then synthesized by an enzyme called Ligase which then forms a whole new stand of DNA! But this process only occurs on the lagging strand because of the direction it is moving in.
test123ok (August 28, 2008 at 7:23 am)
wow that is really complex mechanism..I am interested in how all the steps evolved into the current sequence
decosurf22 (August 27, 2008 at 4:12 pm)
yeah, great video, helped me a lot....
thegreatman99 (August 24, 2008 at 12:39 pm)
Think i get it. the DNA polymerase 3 can only lay down 5' to 3' and so the RNA primer acts as a kind of template so that the DNA can be laid down from it's 3' end. I should have studied earlier but this video is helping. I'm cramming for my test tomorrow!
thegreatman99 (August 24, 2008 at 12:22 pm)
Is the RNA primer like a kind of guide for the DNA polymerase 3 to lay down the DNA? Also, DNA chains are extended only from the 5' to 3' direction but what about the RNA primer. That's going in the 3' to 5' direction...but since that's not DNA...that rule doesn't apply to the RNA primer right?
thegreatman99 (August 24, 2008 at 12:18 pm)
It said that DNA polymerase 3 lays down new DNA on the DNA template and DNA polymerase 1 replaces the already laid down RNA primers..so they're doing different things aren't they?
drgeisme (August 23, 2008 at 11:00 am)
What's the difference between DNA Polymerase 1and DNA Polymerase 3? On the video it says that on the lagging strand, DNA polymerase 3 replaces the RNA primer. A few minutes later it says DNA polyermerase 1 replaces the RNA primer. Can you explain, btw, great video.
nariman89nkf (August 19, 2008 at 3:25 pm)
thanks, that was helpful!!!
TjaraSairin (August 17, 2008 at 11:48 pm)
DNA Polymerase cannot start synthesis de novo, it needs some starting point - which is the primer. |
